netdev - Re: [PATCH net] nfp: bpf: Add an MTU check before offloading BPF

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210929114748.545f7328@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
Date:   Wed, 29 Sep 2021 11:47:48 -0700
From:   Jakub Kicinski <kuba@...nel.org>
To:     Simon Horman <simon.horman@...igine.com>
Cc:     David Miller <davem@...emloft.net>, netdev@...r.kernel.org,
        oss-drivers@...igine.com, Yu Xiao <yu.xiao@...igine.com>,
        Yinjun Zhang <yinjun.zhang@...igine.com>,
        Niklas Söderlund 
        <niklas.soderlund@...igine.com>,
        Louis Peens <louis.peens@...igine.com>
Subject: Re: [PATCH net] nfp: bpf: Add an MTU check before offloading BPF

On Wed, 29 Sep 2021 17:24:21 +0200 Simon Horman wrote:
> From: Yu Xiao <yu.xiao@...igine.com>
> 
> There is a bug during xdpoffloading. When MTU is bigger than the
> max MTU of BFP (1888), it can still be added xdpoffloading.
> 
> Therefore, add an MTU check to ensure that xdpoffloading cannot be
> loaded when MTU is larger than a max MTU of 1888.

There is a check in nfp_net_bpf_load(). TC or XDP, doesn't matter,
we can't offload either with large MTU since the FW helper (used to be) 
able to only access CTM. So the check is on the generic path, adding
an XDP-specific check seems wrong.